(19)
(11) EP 0 867 869 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
23.12.1998 Bulletin 1998/52

(43) Date of publication A2:
30.09.1998 Bulletin 1998/40

(21) Application number: 98104808.5

(22) Date of filing: 17.03.1998
(51) International Patent Classification (IPC)6: G11B 7/007, G11B 7/013, G11B 7/00
// G11B7/26
(84) Designated Contracting States:
AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 28.03.1997 JP 78534/97

(71) Applicant: KABUSHIKI KAISHA TOSHIBA
Kawasaki-shi (JP)

(72) Inventors:
  • Ando, Hideo, c/o Toshiba Kabushiki Kaisha
    Minato-ku, Tokyo 105-8001 (JP)
  • Yamamuro, Mikio, c/o Toshiba Kabushiki Kaisha
    Minato-ku, Tokyo 105-8001 (JP)

(74) Representative: Henkel, Feiler, Hänzel 
Möhlstrasse 37
81675 München
81675 München (DE)

   


(54) Information storage medium and information reproducing apparatus


(57) There are provided an information storage medium, which is manufactured with high yield and is little influenced by a reproducing apparatus, and an information reproducing apparatus capable of performing stable information reproduction. The information storage medium has a pre-groove (1) with a groove-like, continuous projection-and-recess shape and a pre-pit (2) with an intermittent projection-and-recess shape. A level difference (depth or height) of the projection and recess of the pre-pit is substantially equal to that of the pre-groove. Each of the pre-pit and pre-groove has a recording surface wobbling along a predetermined curved line. A reproduction signal with a high S/N can be obtained from the information storage medium having the recording surface by the information reproducing apparatus wherein like a push-pull type tracking error detection method, reproduction light is divided at wave front by a straight line including the center of the reproduction light and a difference in detection light amount between the divided light components.






Search report